Flight model and other early impressions

So i bought the YAK-52, i've waited for SO long a trainer with piston engine and tricycle gear. A slow plane that could do aerobatics. But to be truthful, the YAK-52 was not on my list, mainly due to CCW prop direction that screws up my musclememory :D that said, it's good to be adaptive with different systems.

Anyway. I need to clean up my rudder pedal -shoes because i do need them again! This plane is all about pressing rudder pedal and i like it eventhough it's the wrong foot usually. I love the L39, but being purely aileron plane it is not so exciting to fly... i love the spitfire, but the trim is awful for my controllers (button too slow, axis is too inaccurate), and being tail-wheel.. a little too demanding, although perfectly manageable.

In the YAK the trim control is perfect, the sensation being in the air is exceptional, i love how it rocks and yaws in the air. The engine sounds awesome. It's very good balance between being challening and being very easy. Easy to fly but challenge to fly well.

I hope someday we will see similar slow piston tricycle trainer that is more western.

Few extra questions:

Is there any purpose for flaps / gear lever to be on neutral? Can i skip it? I mean is there any real hazards not-neutralzing them, like loosing air pressure or something? I prefer simple up and down selections...

About cowl flaps and oil cooler.. are there any procedures for them, or only as desired? (like, open for take off, closed for descent, no expections)... I usually keep them open. For me this plane is not so much into systems, it's about stick and rudder ...

Thanks

Afaik, the neutral position for the undercarriage and flaps are intended for instruction use (and safety), so the rear pilot/instructor can set the controls in the correct position if the student pilot makes a mistake. (EN manual, page 30)

I totally agree with your statement: the Yak is a very good balance between being challenging and being easy.

This promises hours of fun and progress!

My understanding is that - yes - it's also better practice to return them to neutral with respect to managing the air pressure...

You can isolate the system from the main air tank and related lines by placing BOTH front and rear levers in neutral IF you suspect a leak for example in the gear or flap system, if there are two pilots in the plane.

With the gear however, if you have the lever neutral you should put the lever to the UP position if the gear is retracted before putting it DOWN or the gear will slam down like it does with the emergency system, it needs both the up and down sides of the actuator pressurized to operate smoothly.

'Gimp

With the gear however, if you have the lever neutral you should put the lever to the UP position if the gear is retracted before putting it DOWN or the gear will slam down like it does with the emergency system, it needs both the up and down sides of the actuator pressurized to operate smoothly.

Nice 'insider' info -:thumbup:

Looking fwd to read from the pilots of the real thing how this latest beta has progressed towards a more fine tuned FDM ?

Just bought the plane and while I've no RL experience of it, the FM still feels pretty convincing to me. Seems an easy AC to fly however, my first circuit went flawlessly straightaway - didn't bend a thing and even managed a greaser on landing!

Certainly a fun bird, that was a $29.99 (with bonuses) well spent. Good job Yo-Yo and crew :thumbup:

Well, I have been away from DCS and the Yak for a little bit, got a chance to fly it again today and seems there may have been some updates. I also recently flew my Yak for a Missing Man Memorial at Fort Rosecrans National Cemetery for a Tuskeegee Airman and captured some in cockpit video of a couple things previously discussed.

The throttle position for start and 40% idle is still way off compared to my plane (timehack 1:08 ). What yields 40% in my plane produces about 60% in the Sim. Still needs work I think.

Starts are much better, air consumption rate for start is modeled correctly I think, however fast starts will result in very little air used, this seems to be programmed to flow for a certain amount of time whether the engine starts or not. See start in my video (timehack 2:15, even with 2 starts I barely used any air, less than .5 atmospheres, starting at 4.5 indicated).

Also noted that the compressor builds air pressure now but it builds up way too fast at idle, should take MUCH longer to refill the tank - as in usually about 10 minutes at power for level flight after a routine engine start, taxi and gear retraction after takeoff.

Prop pitch change is still wrong by factor of 3X, check (timehack 2:50) in video I did in my Yak last week to show how fast the prop works.

Rudder is definitely off in the wrong direction now for most flight regimes, only needs active left rudder at speeds below 150 kph or so, this with takeoff assist off and no change to the base trim setting - not realistic. Right rudder requirement is better than before but not enough required, transition between amount needed for left and right rudder with speed changes is too abrupt and also not enough travel required.

Inverted flight has radically improved, much, much better both in terms of pitch authority and roll balance - I would rate this as fully realistic now.

Pulls to the vertical are very difficult to get a pure wings level pull, more difficult than the real plane - not sure what the issue is here yet, might be controller setup rather than in the model.

I spent some time with a random airshow routine over the NTTR map and would say there has been a marked improvement overall, still work to do before it makes sense to post another video review though.

Last item is the flap pitch moment and drag are still off. Notice in video of my Yak (timehack 4:15) there is next to no pitch change with flap deployment and it is not because of any significant stick deflection on my part.

So looks like improvements are being made, hopefully progress continues to be made.

Once it feels closer to the real Yak I'll do another video.

'Gimp

Well, I have been away from DCS and the Yak for a little bit, got a chance to fly it again today and seems there may have been some updates.

You've provided some great information in this thread - thanks so much for sharing and the videos and detailed explanations. As a real world air ambulance pilot (King Airs and Citations), I've helped tweak some simulator models before and I think developers and the users can really benefit from added input.

With that said, I just bought the Yak a couple days ago and am putting it through its paces. I just wanted to confirm that spins require pro-spin input to maintain (?). I find that I can give it a kick of rudder and full back elevator to get it into the spin, and maintaining back elevator will keep it in the spin with neutral rudder, but all I need to do to recover is basically neutralize the elevator to center and she comes out in very short order (less than a rotation) without having to apply any opposite rudder. Is that pretty legit?

I'm loving the module. Been flying it the last couple days in 2D, but going to give it a whirl in VR today. Nothing better to do than watch the hurricane come up through our area (Charlotte, NC - it will be much weaker by then) (poor, poor Panama City..they are gonna take a hit!).

Thanks again for all the great information!

BeachAV8R

You've provided some great information in this thread - thanks so much for sharing and the videos and detailed explanations. As a real world air ambulance pilot (King Airs and Citations), I've helped tweak some simulator models before and I think developers and the users can really benefit from added input. BeachAV8R

And I can only confirm you did a remarkable job with the fs9 Kingair that was, by that time, my preferred MSFS add-on ever! Well, together with the by that time also great "BlackBox" airbuses...

But indeed, AcroGimp's contributions are Superb!

Unfortunately we can't have the similar for the other modules, with the exception of the UH-1H and probably the Gazelle ( don't own this one... ), so, we will never be able to tell if what we find weird is realistic or not...

I still have some hope to see this Yak-52 fine tuned.

AcroGimp :thumbup: :thumbup: :thumbup:

@BeachAV8R, thanks for the kind words.

The Yak requires pro-spin controls to remain in most 'normal' spins, and recovers quite quickly, between 1/4 and 1/3 turn, the spin behavior in DCS feels pretty accurate at this point although I have not flown a dedicated spin flight in DCS recently.

The real plane will transition from an aerodynamic spin to a hybrid aerodynamic/inertia spin mode under certain loading conditions (aft CG) that requires a long recovery period, pilots get impatient or think they entered wrong correction, then switch to what is in actuality pro-spin inputs and end up riding the plane into the dirt - IMO this is the plane's only real vice - other than that is hand's down the best performance/grin per dollar sportplane out there - tons of character.

'Gimp

Today, "talking" to a CJ-6 pilot, he commented on the marked pitching UP tendency on that aircraft, and, since he's also a user of DCS's Yak-52, he remarked that the DCS Yak was very slight in the pitching UP moment due to flap deloyment, saying that in the CJ-6 it requires prompt aplication of forward stick and then trimming...

How two so similarly looking aircraft can be so different in these detail...

Today, taking to a CJ-6 pilot, he commented on the marked pitching down tendency on that aircraft, and, since he's also a user of DCS's Yak-52, he remerked that the DCS Yak was very slight in the pitching down moment due to flap deloyment, saying that in the CJ-6 it requires prompt aplication of forward stick and then trimming...

 

How two so similarly looking aircraft can be so different in these detail...

CJ 6 pilot here, Its the opposite, when putting flaps down the plane pitches up quite a bit and slows down because of the drag induced by the flaps.

So you to trim and pitch down.

I assume Yak and CJ 6 should behave kind of similar when deploying flaps.(same kind of flaps)

DCS the pitch up forces and drag when deploying flaps seems weak, its hardly noticeable.

I am using a Virpil joystick with extensions, which feels pretty realistic.

Made a video of a power off landing you can see on final when I put flaps down , the nose wants to pitch up and also lots of drag is added.

Have not flown the Yak 52 though, but should not be that different.

Here is a power off landing practice, when I put flpas down see how the nose wants to go up, I need to pitch down to keep the speed.

motoadve, I just corrected my post - I was willing to write UP, and instead wrote down :-/

Ahh the Vortex generator Chang .... small world :) we browse the same forums

motoadve, I just corrected my post - I was willing to write UP, and instead wrote down :-/

Yes I figured that was what you meant.

DCS the pitch up forces and drag when deploying flaps seems weak, its hardly noticeable.

I am using a Virpil joystick with extensions, which feels pretty realistic.

There must be something seriously wrong with your install since drag with the extended flaps is way too high presently.

Even with full throttle you can just barely accelerate to the go speed in level flight, let alone climb and perform the go around as described in the various manuals.

Okay, this is my favourite thread on the forum. I love that we have an experienced pilot of the aircraft giving feedback! AcroGimp, this is awesome!

I was seriously considering buying this module because it is closer to the aircraft I fly IRL.

Closer, not close.

I patiently await the creation of the Piper Arrow or Archer, or Cessna 152 or 172. Great aircraft with a long and distinguished combat service history and therefore perfectly suited to DCS... :)

 

I patiently await the creation of the Piper Arrow or Archer, or Cessna 152 or 172. Great aircraft with a long and distinguished combat service history and therefore perfectly suited to DCS... :)

That makes two of us :-)

Here is what I think about this plane after flying it for a few weeks. I am not a pilot but enjoy it very much.

The plane made little sense from a purely profit based strategy, since most civilian pilots fly other sims. We can be quite thankful that the - undisclosed party who paid for the plane - was so nice to share it with everyone. It's a very nice, professionally made iconic trainer and testbed that literally came from nowhere, it does not cost much and I take it even with small bugs [ongoing development would be a welcome thing though].

I am sure there are ppl who disagree but when I compare it to the roughness of some of the third party planes (that have been in development for years and often make steps backwards) it's already 90% complete. From that point it's an experiment that so far is a success and enriches the DCS experience for those of us who fly with it.

Rudder is definitely off in the wrong direction now for most flight regimes, only needs active left rudder at speeds below 150 kph or so, this with takeoff assist off and no change to the base trim setting - not realistic. Right rudder requirement is better than before but not enough required, transition between amount needed for left and right rudder with speed changes is too abrupt and also not enough travel required.

 

I spent some time with a random airshow routine over the NTTR map and would say there has been a marked improvement overall, still work to do before it makes sense to post another video review though.

 

Last item is the flap pitch moment and drag are still off. Notice in video of my Yak (timehack 4:15) there is next to no pitch change with flap deployment and it is not because of any significant stick deflection on my part.

 

So looks like improvements are being made, hopefully progress continues to be made.

 

Once it feels closer to the real Yak I'll do another video.

 

'Gimp

Hello AcroGimp,

What are your impressions now, after +9 months, since this post?

Has the FM bugs been fixed? does the DCS Yak-52 fly as in RL now?

Are there any major FM or other bugs left?

/Thanx :)

Hey guys thanks for asking.

I have not prepared an update video because the last few times I flew the Yak it still seemed inaccurate, so much so it is not enjoyable for me.

After the recent OB update I figured I would try again and see what I found. So here it is, good, bad and ugly. Understand this was based on half a dozen short flights due to time availability.

I tried with the stock settings and the recommended setting in the Rudder Fix thread on ED Forums, neither are remotely correct IMO compared to my Yak. This was Sim not Game, Takeoff Assistance was off.

The Good:

• Engine power seemed more accurate than I recall from previous.
  
• Roll performance is still about right.
  
• The pitch moment and drag from flaps I would say is finally correct.
  
• Last time I spent considerable time in it the inverted flight performance was correct.
  
• Upright spin behavior was good.
  

The Bad:

• Prop reaction time during the runup (cycling from full forward to full aft and back) is still about 3X too slow.
  
• The nose dive from brake application is still exaggerated by 2X, and the real plane is significantly easier to taxi.
  
• I don't suggest using the aileron or rudder trim settings recommended here in the ED Forums, totally inaccurate at least compared to my Yak.
  
• The deceleration with removal of power in the break is too extreme.
  
• Tumble performance is not quite right but has improved.
  
• It did not seem to require normal pitch and roll inputs during the hammerhead, and the upline is still a little short, 1 to 2 seconds.
  

The Ugly:

• I flew at 170 KPH and 300 KPH, two very different speeds, both feet on the floor, both resulted in ball centered which is nonsense. There is only one single engine prop plane that behaves like that, because it has a complicated Trim Aid Device that automagically positions rudder trim to compensate for power, speed and rate of change in all 3 axes (USAF/USN T-6A/B).
  
• At the top of a loop where a significant amount of left rudder is required to keep the plane from torqueing off IRL I input normal rudder and almost caused a roll off.
  
• This suggests that DCS is either not simulating, or perhaps not accurately simulating Torque and Slipstream/P-Factor effects, at least for this module.
  

I'll try and spend more time for a more in depth review and possibly record another video as well as experiment with trim settings in the LUA to see if there is a setting or combination of settings that more accurately reflect the real plane's performance.

DISCO

AcroGimp is your auto trim off? It should be in general settings for all planes. It was added without much notice a few months ago

Thanks AeriaGloria, yes AutoTrimmer is off for all aircraft and Takeoff Assistance is off for the Yak-52.

DISCO

Acro,

Do you also have that frankly bizarre rudder behaviour introduced a few patches ago ? The rudder now stays left of center when flying, and seems to try and correct yaw on takeoff, which is now somehow much reduced.

Every assist imaginable is off and the non-functioning trim tabs are all centered.

Best answer I could get from ED people is that it is indeed a bug, but nothing else.